The channel conduction condition of field-effect transistor is determined by surface effect of semiconductor, and controlling the hole and electronic exhaustion or accumulation on the active layer surface of the semiconductor by the gate electrode voltage, so as to achieve switching function. Because of the simple principle, mature technology and high reliability of the field-effect transistor, it has been widely applied in the electronic devices and integrated circuits. The performance of the field-effect transistor is effected by many factors such as craft, process, material and device structure, in which the channel material and device structure are fundamentally determining the mobility and efficiency of the field-effect transistor.
Since quantum size effects of the colloidal quantum has discovered, thin film technology is greatly applied in the field of electronics and optoelectronics. Based on the advantages of adjustable size gap, small exciton binding energy, high electrification and photoluminescence efficiency, and inexpensive solution process, quantum dots has been successfully applied in thin film optoelectronic devices such as solar cells and light emitting diodes. However, the charge transport properties and applications of the quantum dots film field-effect transistors still rarely reported, far behind the commercial silicon transistors and the organic field-effect transistors.
The semiconductor quantum dots colloid realizes an effective overlap and coincidence of quantum electrons or hole wave functions by close-packed self-assembly, and will form a new type of “artificial thin film”. This solid film not only retains the unique tunability of quantum dots material properties, but also has high carrier mobility and electrical conductivity. Compared with silicon-based transistors, the field-effect transistor with quantum dots as the carrier transport layer has the advantages of simple manufacturing process, low cost, good weight and good flexibility. These features, which make the quantum dots field effect transistor become an important component of the future electronics industry, it can be widely used in smart cards, memory, electronic trademarks, margin matrix displays and sensors.
Currently, carbon element is one of the most abundant materials in nanostructures with varying properties, such as carbon quantum dots, carbon nanotubes and graphene all have excellent chemical, physical, mechanical and electrical properties that bringing great research interests and experimental applications for researchers. The carbon-based electronics has attracted more and more attentions because of its small size, fast speed, low power consumption, simple technology and other characteristics. Among many carbon nanomaterials, the carbon quantum dots are zero-dimensional nanoparticles with size less than 10 nm, because of the low cost, low toxicity, long-term stability, efficient carrier generation ability, easy to prepare, and the optical response is able to be adjusted by the particle size, carbon quantum dots become the ideal alternative material to the traditional semiconductor quantum dots.